1. Field of the Invention
The present invention relates to the use of avocado peels in order to obtain avocado unsaponifiable enriched in saturated aliphatic hydrocarbons and in sterols. Advantageously, said avocado peels account for 5 to 50% by weight relative to the total weight of avocado used. The invention also relates to a method for obtaining avocado unsaponifiable enriched in saturated aliphatic hydrocarbons and in sterols from at least avocado peels, said avocado peels accounting for 5 to 50% by weight relative to the total weight of avocado used. The invention also relates to an avocado unsaponifiable enriched in saturated aliphatic hydrocarbons and in sterols, obtainable by this method. Lastly, the invention relates to one such avocado unsaponifiable enriched in saturated aliphatic hydrocarbons and in sterols, for use as a drug, advantageously in the prevention and/or treatment of conjunctive tissue disorders such as arthrosis, articular pathologies such as rheumatism, or periodontal diseases such as gingivitis or periodontitis.
2. Description of Related Art
Since the 1990s, the worldwide market for the avocado has become diversified. The principal channels remain directed mainly towards export or local markets, depending on the producer country. However, the volumes destined for industry are growing rapidly and are generally related to the processing of fresh pulp into edible products, as well as the production of avocado oil of edible or cosmetic quality.
These latter applications, although they may remain marginal relative to the tonnages dedicated to the marketing of the avocado as a fresh market fruit, make it possible to make use of fruits discarded from the sorting process and fruits rejected by this market. These represent a raw material with a much more acceptable entry cost.
These processing industries are chiefly devoted to adding value to avocado pulp. As a result they generate by-products, resulting from the pulp removal process. For example, the industries that produce guacamole and edible and cosmetic avocado oil, obtained by centrifugation, use only avocado pulp. Thus, very large quantities of co-products, namely the avocado fruits' seeds and peels, are generated which are not made profitable use of by the food processing industry.
Avocado oil is indeed concentrated mainly in the storage cells of the pulp, i.e., the idioblasts. The avocado peel is low in oil and thus holds only little interest for oil producers.
Furthermore, in the traditional avocado oil extraction processes, it is generally sought to remove the avocado peels to the maximum extent possible. To this end, the fruits are thus peeled before oil extraction, because avocado peel contains a high concentration of chlorophylls and pigments which color and darken the oil finally obtained. They can also impact the oxidative and chemical stability of the oil, as well as its suitability for refining.
Markets have been studied and developed to try to develop these by-products, namely the peels and the seeds, such as spreading, mulching, horticulture and animal feeds, but they do not provide high added-value.
However, even if the constituent parts of the avocado, namely the peels and the seeds, are naturally low in oil, they contain compounds constituent of the unsaponifiable with a potential as active ingredients and with high added value.
Nevertheless, as these compounds are in small quantities in these parts of the fruit, such as the peels, they are as a result difficult to reach and to extract.
The high water content of avocados makes them difficult to work with and makes it nearly impossible to process them by the physical extraction methods known to those skilled in the art and under acceptable economic conditions.
Furthermore, the low content of oil and of active compounds in avocado peels precludes the application of a physical treatment by mechanical pressure, this technique being insufficiently effective to process products with oil contents lower than 10%.
Only solvent extraction thus appears possible, although beyond the fact that this method requires a complex technology, it is well-known to be expensive, polluting and toxic for man and the environment.
There thus existed a need to find a method that makes it possible, at low cost, to add value to these active compounds potentially available in easily accessible co-products.
In the past few decades, knowledge of the chemistry of the avocado has expanded considerably. Several families of compounds, for example, have been isolated and identified from the fruits and many studies have been carried out to demonstrate their biological activities. The composition of the unsaponifiable fraction of avocado oil was studied in particular.
The co-products of the avocado processing industry, and notably the peels, are low in oil, but contain all or some of the constituent compounds of the unsaponifiable, in particular compounds of the aliphatic hydrocarbons type with typically an odd number of carbon atoms, of molecular weight near 400 g/mol, and known for their protective and texturing properties.
Furthermore, plant sterols and phytosterols are also constituents of the avocado unsaponifiable and are recognized for, among other things, their anticholesteremic properties, making it possible to limit cardiovascular risks, and for their anti-inflammatory properties.
There has thus been interest in finding a method that makes it possible to extract at lower cost some constituent compounds of avocado unsaponifiable, as mentioned above, in particular from co-products or by-products of the avocado processing industry, such as avocado peels.
The present invention fills this need. The Applicant has thus discovered a novel method for obtaining avocado unsaponifiable enriched in saturated aliphatic hydrocarbons and in sterols, notably from avocado peels.